Preoperative Aspirin Use and Its Effect on Adverse Events in Patients Undergoing Cardiac Operations

Preoperative continuation of aspirin before isolated heart valve surgery and postoperative bleeding and transfusion: a single-center retrospective study

BACKGROUND

The risks and benefits of preoperative aspirin continuation in patients undergoing isolated heart valve replacement surgery are unclear. We investigated the effect of aspirin continuation on the risk of bleeding and transfusion in these patients.

METHODS

In this single center, retrospective study, among 474 adult patients who underwent isolated heart valve surgery between April 2013 and June 2018, 269 continued aspirin within 5 days before surgery (aspirin group) and 205 patients did not take or stopped aspirin no later than 5 days before surgery (non-aspirin group). The chi-square test, the Mann-Whitney U-test, and the Student's T-test were used to compare data between the groups. Univariate and Multivariate logistic regressions were used to assess crude and adjusted relationships between outcome and exposure.

RESULTS

The primary outcome, red blood cell (RBC) transfusion, occurred in 59 patients (22%) of the aspirin group and in 24 patients (12%) of the non-aspirin group (p = 0.004). After adjustment for confounding factors, continuation of aspirin was no longer associated with RBC transfusion (aOR1.8;95%CI,0.98-3.2;p = 0.06). The amount of allogenic blood products, the incidence of surgical re-exploration for bleeding, the volume of re-transfused cell-saved blood, and the cumulative chest tube drainage during the first 24 postoperative hours were similar between groups.

CONCLUSION

Preoperative continuation of aspirin in patients undergoing isolated heart valve surgery is neither associated with a higher incidence of RBC transfusion, nor with larger perioperative blood loss, or more frequent surgical revision for bleeding.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT05151796).

Perioperative Management of Antiplatelet Therapy: A Systematic Review and Meta-analysis

OBJECTIVE

To summarize the available evidence about the perioperative management of patients who are receiving long-term antiplatelet therapy and require elective surgery/procedures.

METHODS

This systematic review supports the development of the American College of Chest Physicians guideline on the perioperative management of antiplatelet therapy. A literature search of MEDLINE, EMBASE, Scopus and Cochrane databases was conducted from each database's inception to July 16, 2020. Meta-analyses were conducted when possible.

RESULTS

In patients receiving long-term antiplatelet therapy and undergoing elective noncardiac surgery, the available evidence did not show a significant difference in major bleeding between a shorter vs longer antiplatelet interruption, with low certainty of evidence (COE). Compared with patients who received placebo perioperatively, aspirin continuation was associated with increased risk of major bleeding (relative risk [RR], 1.31; 95% CI, 1.15-1.50; high COE) and lower risk of major thromboembolism (RR, 0.74; 95% CI, 0.58-0.94; moderate COE). During antiplatelet interruption, bridging with low-molecular-weight heparin was associated with increased risk of major bleeding compared with no bridging (RR, 1.86; 95% CI, 1.24-2.79; very low COE). Continuation of antiplatelets during minor dental and ophthalmologic procedures was not associated with a statistically significant difference in the risk of major bleeding (very low COE).

CONCLUSION

This systematic review summarizes the current evidence about the perioperative management of antiplatelet therapy and highlights the urgent need for further research, particularly with the increasing prevalence of patients taking 1 or more antiplatelet agents.

Preoperative Functional Platelet Number Is Inversely Associated With 30-Day Mortality After Cardiac Surgery: A Retrospective Cohort Study

Background. We hypothesize that preoperative functional platelet number (platelet count multiplied by platelet aggregation percentage) are associated with 30-day mortality after cardiac surgery. Methods. We linked our preoperative testing database with the STS (Society of Thoracic Surgeon) database to form a study cohort of 1390 patients who had cardiac surgeries between January 2008 and December 2013. Preoperative tests of platelet count and platelet aggregation were routinely performed on all cardiac surgical patients within 24 hours before entering the operating room. Multiple logistic regression models were used to determine whether functional platelet number are associated with 30-day mortality, modified composite major adverse cardiocerebral events, postoperative renal failure or requirement for new renal replacement therapy, and reoperation for bleeding. Log-linear models were used to examine whether functional platelet numbers are associated with hospital length of stay and intensive care unit length of stay. Results. Functional platelet number had an inverse association with 30-day mortality, and each 50 × 10⁹/L increase in functional platelet number resulted in decreased 30-day mortality (odds ratio of 0.767 with 95% confidence interval = 0.591-0.996). For secondary outcomes, functional platelet number was neither associated with major adverse cardiocerebral event nor length of stay. However, we found that each 50 × 10⁹/L increase in functional platelet number was associated with decreased reoperations for bleeding (odds ratio of 0.778 with 95% confidence interval = 0.636-0.951). Conclusions. The preoperative functional platelet number had significant associations with 30-day mortality after cardiac surgery. Functional platelet number could be used to guide timing of cardiac surgery, especially as more and more patients are receiving antiplatelet medications nowadays.

Use of preoperative aspirin in combined coronary and valve operations

BACKGROUND

The aim of this study was to determine the relationship between preoperative aspirin use and postoperative outcomes in patients undergoing combined coronary artery bypass grafting and valve operations.

METHODS

All combined coronary artery bypass grafting and valve procedures from 2008 to 2015 at our institution were identified. After exclusions, patients were stratified according to those that received preoperative aspirin and those who did not. Propensity score methodology was used to match the 2 groups using baseline and operative characteristics. Logistic regression models were then developed to assess differences in postoperative outcomes between groups.

RESULTS

Of the 563 patients identified, 534 met inclusion criteria: preoperative aspirin = 327 (61.2%), no preoperative aspirin = 207 (38.8%). After propensity matching, 194 patient pairs were analyzed, with no significant differences in preoperative characteristics. No significant differences were observed between the preoperative aspirin and no preoperative aspirin groups in rates of 30-day mortality (3.6% vs 4.1%, P = 1.00), major adverse cardiovascular events (23.2% vs 24.2%, P = .91), or 30-day readmission (12.4% vs 11.9%, P = 1.00), among others.

CONCLUSION

Preoperative aspirin use in patients undergoing combined coronary artery bypass grafting and valve operations was not associated with significant differences in major postoperative outcomes. Large-scale, randomized trials are needed to better establish the role of preoperative aspirin in this population.